Valves, such as inline check valves or other valves, may include sealing structures between two valve components to prevent leakage of fluid and/or vapor. In fuel tank applications, for example, the seal prevents fuel from leaking between layers or to the atmosphere. However, various conditions may weaken the sealing capabilities of the seal. For example, high internal pressures in the valve and/or a high differential between the pressures inside and outside the valve may cause leakage. Contamination, flash, or other debris on the sealing surface may also compromise the seal.